Public health policy, evidence, and causation: lessons from the studies on obesity.

The paper addresses the question of how different types of evidence ought to inform public health policy. By analysing case studies on obesity, the paper draws lessons about the different roles that different types of evidence play in setting up public health policies. More specifically, it is argued that evidence of difference-making supports considerations about 'what works for whom in what circumstances', and that evidence of mechanisms provides information about the 'causal pathways' to intervene upon.